When you’re off-grid, an inverter is the key to powering the gear that makes life easier. Whether it’s charging a laptop, running power tools, or brewing coffee at camp, a pure sine wave inverter converts your 12V DC battery power into the 110V AC power that household devices need.
But with different sizes and options available, how do you pick the right one? This guide explains power requirements, inverter sizing, battery capacity, and why pure sine wave technology matters.
WHY AN INVERTER IS ESSENTIAL
Your vehicle’s battery produces DC power, but most everyday appliances require AC power. An inverter bridges the gap, giving you safe, reliable power anywhere. The right inverter runs appliances without the risk of damaging sensitive electronics and handles start-up surges from high-demand devices
Still not sure what an Inverter is? See our article explaining inverters.
HOW MUCH POWER DO COMMON DEVICES USE?
To choose the right sized inverter, start by listing the appliances you want to run and their wattage rating (usually found on the device or in the manual).
Typical examples:
- Laptop: 100–150W
- Coffee machine: 1000–1500W
- Microwave: ~1000W (higher at start-up)
- Power tools: often exceed rated wattage during start-up
Tip: Always add at least 20% extra capacity to account for surges or future upgrades.
HOW TO CHOOSE THE RIGHT SIZE INVERTER
Don’t just match your inverter size to the running wattage of your largest appliance. Factor in start-up surges and choose with headroom.
Example: If you plan to run a 1000W microwave, select a 1500W or 2000W inverter to handle surge power and maintain stable operation.
Remember: inverter ratings refer to continuous output, so extra capacity ensures reliable performance.
WHICH MODEL DO I NEED?
| MODEL | SUITABLE APPLICATIONS |
| R-12-400RS-NA | Phone and camera chargers, CD players, GPS, computers, CPAP machines, laptops |
| R-12-1000RS-NA | Any of the above plus TVs, power tool battery chargers |
| R-12-1500RS-NA | Any of the above plush capsule coffee machines |
| R-12-2000RS-NA | Any of the above plus irons, hairdryers, microwaves |
| R-12-3000RS-NA | Any of the above plus heaters, espresso machines, kettles |
WHAT BATTERIES DO YOU NEED TO RUN AN INVERTER?
The larger the inverter, the more battery capacity you’ll need. A simple rule is that every 100Ah of battery can power a 1000W inverter but always best to check with a professional on installation, providing them with information on what you will be powering.
To avoid draining your starter battery, pair your inverter with a DC to DC charger. This keeps both your starter and auxiliary batteries charged, protecting your vehicle and extending your off-grid time.
SHOULD YOU JUST BUY THE BIGGEST INVERTER?
Bigger isn’t always better. While higher-wattage inverters let you power more appliances, there are trade-offs:
- They take up more space and add weight
- Larger units often consume more standby power if left on
- They require higher battery capacity to sustain output
Tip: To save energy, turn your inverter off when not in use. A remote switch makes this quick and easy.
WHY PURE SINE WAVE MATTERS
Not all inverters deliver the same quality of power. Choosing a pure sine wave inverter is essential for sensitive electronics and safe, efficient operation.
REDARC Pure Sine Wave Inverters provide:
- Clean, stable power for laptops, chargers, and medical devices
- Lower heat and noise output
- Fully isolated input/output for overload and short-circuit protection
This ensures your appliances and electronics run safely, even in remote conditions.
Every setup is different, and the best inverter for you depends on what you need to power and how long you’ll be off-grid. By calculating your energy requirements, planning for surges, and considering battery capacity, you can choose an inverter that delivers reliable performance without wasting power.
REDARC’s range of pure sine wave inverters are designed for rugged use and trusted by travelers, campers, trade professionals, and overlanders worldwide.
Explore the full REDARC inverter range or visit the Tech Help section for more advice on choosing the right model for your rig.
